How do I Transfer contacts from google to iphone

Add your Google mail account to your iPhone, then sync the contacts.

Here is how to add a mail account to your iPhone --> Add an email account to your iPhone or iPad - Apple Support

Contacts are synced from whatever mail account you are using. If you are using Google for contacts, you have a Gmail email address. Add that account to mail, then select the Contacts switch in the Mail account and it will populate your Contacts on the phone. You may have to check the upper left corner of your Contacts page to ensure that you have GMail or Google selected to display.